A buck converter is a voltage regulator for generating a regulated output voltage using a supply voltage higher than the regulated output voltage.
A buck converter may be implemented, for example, using current mode control, cf. Mark Hartman, “Inside current-mode control” in: “Power designer”, No. 106. A current mode control circuit may be referred to herein as a switched mode regulator. A switched mode regulator may have a relatively low bandwidth which is limited by the switching frequency. In the case of quick load transients, this limitation may imply a drop on the output voltage value. Such a drop may, for instance, cause an unintended reset of, e.g., a digital device supplied by the switched mode regulator. Furthermore, in the event of a negative current transient, i.e., a load current decrease the current in the inductor typically included in the switched mode regulator, may flow into a capacitor creating a voltage overshoot.
An overshoot problem may notably occur when the switched mode regulator is used to supply one or more microcontrollers. In recent years, microcontrollers tended to require an ever higher current capability in a limited voltage range, to allow for higher operating frequencies. A voltage overshoot may however be destructive.